1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T T.832 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (08/2016) SERIES T: TERMINALS FOR TELEMATIC SERVICES Still-image compression | JPEG XR Information technology JPEG XR image coding system Image coding specification Reco
2、mmendation ITU-T T.832 ITU-T T-SERIES RECOMMENDATIONS TERMINALS FOR TELEMATIC SERVICES Facsimile Framework T.0T.19 Still-image compression Test charts T.20T.29 Facsimile Group 3 protocols T.30T.39 Colour representation T.40T.49 Character coding T.50T.59 Facsimile Group 4 protocols T.60T.69 Telematic
3、 services Framework T.70T.79 Still-image compression JPEG-1, Bi-level and JBIG T.80T.89 Telematic services ISDN Terminals and protocols T.90T.99 Videotext Framework T.100T.109 Data protocols for multimedia conferencing T.120T.149 Telewriting T.150T.159 Multimedia and hypermedia framework T.170T.189
4、Cooperative document handling T.190T.199 Telematic services Interworking T.300T.399 Open document architecture T.400T.429 Document transfer and manipulation T.430T.449 Document application profile T.500T.509 Communication application profile T.510T.559 Telematic services Equipment characteristics T.
5、560T.649 Still-image compression JPEG 2000 T.800T.829 Still-image compression JPEG XR T.830T.849 Still-image compression JPEG-1 extensions T.850T.899 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T T.832 (08/2016) i Recommendation ITU-T T.832 Information technology
6、 JPEG XR image coding system Image coding specification Summary Recommendation ITU-T T.832 specifies a coded image format, referred to as JPEG XR, which is designed primarily for the storage and interchange of continuous-tone photographic content. The main body of the text specifies the syntax and s
7、emantics of JPEG XR coded images and the associated decoding process. Annex A specifies a tag-based file storage format for the storage and interchange of such coded images. Annex B specifies profiles and levels that determine conformance requirements for classes of encoders and decoders. Aspects of
8、 colour imagery representations and colour management are discussed in Annex C. The typical expected encoding process is described in Annex D. The first edition of Recommendation ITU-T T.832 was approved in 03/2009. Corrigendum 1 (approved 12/2009) contained a set of various minor corrections. Corri
9、gendum 2 (approved 05/2011) contained additional minor corrections. The second edition (approved 01/2012) included additional minor corrections. This third edition (approved 08/2016) adds a media type specification for use in various Internet protocols to identify images encoded according to the tag
10、-based format specified in Annex A of this Recommendation. This text was developed as a twin text Recommendation corresponding to ISO/IEC 29199-2 in collaboration with ISO/IEC JTC 1/SC 29/WG 1 (JPEG). History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T T.832 2009-03-16 16 11.100
11、2/1000/9721 1.1 ITU-T T.832 (2009) Cor.1 2009-12-14 16 11.1002/1000/10647 1.2 ITU-T T.832 (2009) Cor. 2 2011-05-14 16 11.1002/1000/11317 2.0 ITU-T T.832 2012-01-13 16 11.1002/1000/11471 3.0 ITU-T T.832 2016-08-13 16 11.1002/1000/12959 * To access the Recommendation, type the URL http:/handle.itu.int
12、/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T T.832 (08/2016) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunic
13、ations, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunicat
14、ions on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure
15、laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommun
16、ication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these m
17、andatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draw
18、s attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or
19、 others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represen
20、t the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2017 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T T.832 (08/2016)
21、iii CONTENTS Page 1 Scope 1 2 Normative references 1 3 Definitions 1 4 Abbreviations . 4 5 Conventions 5 5.1 Conformance language 5 5.2 Operators . 5 5.2.1 Arithmetic operators 5 5.2.2 Logical operators . 6 5.2.3 Relational operators. 6 5.2.4 Bit-wise operators . 6 5.2.5 Assignment operators 7 5.2.6
22、 Precedence order of operators . 7 5.2.7 Pseudocode operations 8 5.2.8 Mathematical functions . 9 5.3 Syntax and semantics notation 12 5.3.1 Method of specifying syntax in tabular form 12 5.3.2 SYNTAX_ELEMENT_EXAMPLE semantics . 13 5.3.3 Syntax functions 13 5.4 Formatting conventions . 13 5.4.1 Vari
23、able and array naming conventions 13 5.4.2 Data structure naming conventions . 14 5.4.3 Syntax element naming conventions . 14 5.4.4 Syntax structure naming conventions 14 5.4.5 Naming conventions for mnemonic constants. 14 5.4.6 Naming conventions for numerical values 14 5.4.7 Array dimensions conv
24、ention 14 5.5 Global variables 15 5.5.1 Image variables . 15 5.5.2 Image plane variables 15 5.5.3 Tile variables . 16 5.5.4 Macroblock variables 16 5.5.5 Data structures for adaptive VLC table selection 17 5.5.6 Adaptive coefficient normalization data structure instances . 19 5.5.7 Adaptive CBPHP pr
25、ediction data structure instance . 19 5.5.8 Adaptive count CBPLP variables 20 5.6 Adaptive VLC deltaDisc tables . 20 5.7 Adaptive inverse scanning tables 20 6 Image and codestream structures 20 6.1 General 20 6.2 Image planes and component arrays . 21 6.3 Image windowing 21 6.4 Image partitioning .
26、21 6.5 Transform coefficients and frequency bands 22 6.6 Codestream structure . 23 6.7 Precision and word length . 24 7 Overview of decoder 24 iv Rec. ITU-T T.832 (08/2016) 7.1 General 24 7.2 Overview of parsing process . 25 7.2.1 Overview of image layer codestream parsing . 25 7.2.2 Overview of til
27、e layer codestream parsing 25 7.2.3 Overview of macroblock layer codestream parsing 25 7.3 Overview of the decoding process 25 7.3.1 Overview of coefficient mapping 25 7.3.2 Overview of coefficient prediction 26 7.3.3 Overview of dequantization 26 7.3.4 Overview of sample reconstruction . 26 7.3.5 O
28、verview of output formatting 27 8 Syntax, semantics, and parsing process 27 8.1 General 27 8.2 CODED_IMAGE( ) 28 8.2.1 Syntax structure . 28 8.2.2 SubsequentBytes . 28 8.2.3 RESERVED_A_BYTE . 28 8.2.4 VLW_ESC( ) . 29 8.3 IMAGE_HEADER( ) 30 8.3.1 Syntax structure . 30 8.3.2 GDI_SIGNATURE . 30 8.3.3 R
29、ESERVED_B . 31 8.3.4 HARD_TILING_FLAG 31 8.3.5 RESERVED_C . 31 8.3.6 TILING_FLAG . 31 8.3.7 FREQUENCY_MODE_CODESTREAM_FLAG 31 8.3.8 SPATIAL_XFRM_SUBORDINATE . 31 8.3.9 INDEX_TABLE_PRESENT_FLAG 32 8.3.10 OVERLAP_MODE . 32 8.3.11 SHORT_HEADER_FLAG . 32 8.3.12 LONG_WORD_FLAG . 32 8.3.13 WINDOWING_FLAG
30、33 8.3.14 TRIM_FLEXBITS_FLAG 33 8.3.15 RESERVED_D . 33 8.3.16 RED_BLUE_NOT_SWAPPED_FLAG . 33 8.3.17 PREMULTIPLIED_ALPHA_FLAG 33 8.3.18 ALPHA_IMAGE_PLANE_FLAG . 34 8.3.19 OUTPUT_CLR_FMT . 34 8.3.20 OUTPUT_BITDEPTH 35 8.3.21 WIDTH_MINUS1 . 35 8.3.22 HEIGHT_MINUS1 . 35 8.3.23 NUM_VER_TILES_MINUS1 36 8.
31、3.24 NUM_HOR_TILES_MINUS1 . 36 8.3.25 TILE_WIDTH_IN_MBn 36 8.3.26 TILE_HEIGHT_IN_MBn 36 8.3.27 TOP_MARGIN . 37 8.3.28 LEFT_MARGIN . 37 8.3.29 BOTTOM_MARGIN 37 8.3.30 RIGHT_MARGIN 37 8.4 IMAGE_PLANE_HEADER( ) . 37 8.4.1 Syntax structure . 37 8.4.2 INTERNAL_CLR_FMT . 38 8.4.3 SCALED_FLAG . 39 8.4.4 BA
32、NDS_PRESENT 39 8.4.5 RESERVED_E_BIT . 39 8.4.6 CHROMA_CENTERING_X 40 8.4.7 RESERVED_F 40 8.4.8 RESERVED_G_BIT . 40 8.4.9 CHROMA_CENTERING_Y 40 Rec. ITU-T T.832 (08/2016) v 8.4.10 RESERVED_H . 41 8.4.11 NUM_COMPONENTS_MINUS1 41 8.4.12 NUM_COMPONENTS_EXTENDED_MINUS16. 41 8.4.13 SHIFT_BITS . 41 8.4.14
33、LEN_MANTISSA . 41 8.4.15 EXP_BIAS 41 8.4.16 DC_IMAGE_PLANE_UNIFORM_FLAG . 41 8.4.17 RESERVED_I_BIT 42 8.4.18 LP_IMAGE_PLANE_UNIFORM_FLAG 42 8.4.19 RESERVED_J_BIT 42 8.4.20 HP_IMAGE_PLANE_UNIFORM_FLAG . 42 8.4.21 BYTE_ALIGNMENT_BIT 42 8.4.22 DC_QP( ) 42 8.4.23 LP_QP( ) . 43 8.4.24 HP_QP( ) . 44 8.5 I
34、NDEX_TABLE_TILES( ) . 45 8.5.1 Syntax structure . 45 8.5.2 INDEX_TABLE_STARTCODE 45 8.5.3 IndexOffsetTilen . 45 8.6 PROFILE_LEVEL_INFO( ) . 45 8.6.1 Syntax structure . 45 8.6.2 PROFILE_IDC 46 8.6.3 LEVEL_IDC . 46 8.6.4 RESERVED_L 46 8.6.5 LAST_FLAG 46 8.7 CODED_TILES( ) 46 8.7.1 Syntax structure . 4
35、6 8.7.2 TILE_SPATIAL( ) 47 8.7.3 TILE_DC( ) . 48 8.7.4 TILE_HEADER_DC( ) . 48 8.7.5 TILE_LOWPASS( ) 49 8.7.6 TILE_HEADER_LOWPASS( ) 49 8.7.7 TILE_HIGHPASS( ) . 50 8.7.8 TILE_HEADER_HIGHPASS( ) . 51 8.7.9 TILE_FLEXBITS( ) 51 8.7.10 Tile-level semantics. 51 8.7.11 MB_DC( ) . 54 8.7.12 DECODE_DC( ) . 5
36、5 8.7.13 DECODE_ABS_LEVEL( ) . 55 8.7.14 Macroblock DC( ) semantics . 56 8.7.15 Macroblock low-pass 57 8.7.16 General 57 8.7.17 Coded block pattern high-pass (CBPHP) 61 8.7.18 Macroblock high-pass . 67 8.7.19 Macroblock FLEXBITS 75 8.8 Adaptive VLC code table selection . 76 8.8.1 General 76 8.8.2 Ad
37、aptive VLC deltaDisc tables . 77 8.8.3 Initialization 79 8.8.4 Update of adaptive VLC code table selection . 81 8.9 Adaptation of CBPLP state variables 84 8.9.1 General 84 8.9.2 InitializeCountCBPLP( ) . 84 8.9.3 UpdateCountCBPLP( ) 84 8.10 Adaptive CBPHP prediction . 84 8.10.1 InitializeCBPHPModel(
38、 ) 84 8.10.2 UpdateCBPHPModel( ). 84 8.11 Adaptive inverse scanning 85 8.11.1 Adaptive inverse scanning tables 85 vi Rec. ITU-T T.832 (08/2016) 8.11.2 InitializeAdaptiveScanLP( ) 86 8.11.3 InitializeAdaptiveScanHP( ) . 86 8.11.4 ResetTotalsAdaptiveScanLP( ) . 86 8.11.5 ResetTotalsAdaptiveScanHP( ) .
39、 86 8.11.6 AdaptiveLPScan( ) 87 8.11.7 AdaptiveHPScan( ) 87 8.12 Adaptive coefficient normalization . 88 8.12.1 InitializeModelMB( ) 88 8.12.2 UpdateModelMB( ) . 88 9 Decoding process . 89 9.1 General 89 9.2 Image decoding . 89 9.3 Image plane decoding 90 9.4 Tile transform coefficient processing 90
40、 9.4.1 Overview . 90 9.4.2 DC transform coefficient decoding . 91 9.4.3 Low-pass transform coefficient decoding . 91 9.4.4 High-pass transform coefficient decoding . 91 9.5 Coefficient remapping . 92 9.5.1 DC coefficient remapping . 92 9.5.2 Low-pass coefficient remapping . 92 9.5.3 High-pass macrob
41、lock coefficient remapping . 93 9.5.4 High-pass block coefficient remapping . 93 9.6 Transform coefficient prediction . 93 9.6.1 DC coefficient prediction 93 9.6.2 Low-pass prediction 96 9.6.3 High-pass prediction . 98 9.7 Derivation of quantization parameters 102 9.7.1 Derivation of DC quantization
42、 parameters 102 9.7.2 Derivation of low-pass quantization parameters . 103 9.7.3 Derivation of high-pass quantization parameters 104 9.8 Dequantization 105 9.8.1 Dequantization of DC coefficients 105 9.8.2 Dequantization of low-pass coefficients . 106 9.8.3 Dequantization of high-pass coefficients 1
43、06 9.8.4 QuantMap( ) 107 9.9 Sample reconstruction . 108 9.9.1 Overview . 108 9.9.2 First level inverse transform 108 9.9.3 First level overlap filtering 109 9.9.4 Second level coefficient combination . 121 9.9.5 Second level inverse transform . 122 9.9.6 Second level overlap filtering 123 9.9.7 Inv
44、erse transform basic operations 129 9.9.8 Overlap filtering functions 132 9.10 Output formatting 136 9.10.1 Overview . 136 9.10.2 Output formatting stage . 136 9.10.3 Sampling conversion . 137 9.10.4 Conversion from INTERNAL_CLR_FMT to OUTPUT_CLR_FMT 139 9.10.5 AddBias( ) . 142 9.10.6 ComputeScaling
45、( ) 143 9.10.7 Postscaling process 144 9.10.8 Clipping and packing stage . 146 Annex A Tag-based file format . 150 Rec. ITU-T T.832 (08/2016) vii A.1 General 150 A.2 Normative references 150 A.2.1 Identical Recommendations | International Standards 150 A.2.2 Paired Recommendations | International St
46、andards equivalent in technical content . 150 A.2.3 Additional references 150 A.3 Definitions . 150 A.4 Abbreviations 151 A.5 FILE_HEADER( ) 151 A.5.1 Syntax structure . 151 A.5.2 FIXED_FILE_HEADER_II_2BYTES . 151 A.5.3 FIXED_FILE_HEADER_0XBC_BYTE 151 A.5.4 FILE_VERSION_ID . 151 A.5.5 FIRST_IFD_OFFS
47、ET . 151 A.6 IMAGE_FILE_DIRECTORY( ) . 152 A.6.1 Syntax structure . 152 A.6.2 NUM_ENTRIES . 152 A.6.3 ZERO_OR_NEXT_IFD_OFFSET . 152 A.7 IFD_ENTRY( ) . 152 A.7.1 Syntax structure . 152 A.7.2 FIELD_TAG . 154 A.7.3 ELEMENT_TYPE 154 A.7.4 NUM_ELEMENTS . 155 A.7.5 VALUES_OR_OFFSET . 155 A.7.6 DOCUMENT_NA
48、ME 155 A.7.7 IMAGE_DESCRIPTION 155 A.7.8 EQUIPMENT_MAKE 155 A.7.9 EQUIPMENT_MODEL 155 A.7.10 PAGE_NAME. 156 A.7.11 PAGE_NUMBER . 156 A.7.12 SOFTWARE_NAME_VERSION 156 A.7.13 DATE_TIME 156 A.7.14 ARTIST_NAME . 157 A.7.15 HOST_COMPUTER . 157 A.7.16 COPYRIGHT_NOTICE . 157 A.7.17 COLOR_SPACE . 158 A.7.18
49、 PIXEL_FORMAT . 158 A.7.19 SPATIAL_XFRM_PRIMARY . 166 A.7.20 IMAGE_TYPE 166 A.7.21 PTM_COLOR_INFO( ) 167 A.7.22 PROFILE_LEVEL_CONTAINER( ) . 172 A.7.23 IMAGE_WIDTH 172 A.7.24 IMAGE_HEIGHT . 172 A.7.25 WIDTH_RESOLUTION 172 A.7.26 HEIGHT_RESOLUTION . 172 A.7.27 IMAGE_OFFSET . 172 A.7.28 IMAGE_BYTE_COUNT 172 A.7.29 ALPHA_OFFSET . 173 A.7.30 ALPHA_BYTE_COUNT . 173 A.7.31 IMAGE_BAND_PRESENCE. 173 A.7.32 ALPHA_BAND_PRESENCE 173 A.7.33 PADDING_DATA 173 Annex B Profiles and levels. 174 B.1 General 174 B.2 Profiles
